DESCRIPTION: This Core provides a set of resources (space and equipment), technical expertise, and routine services including maintaining and passing cell lines, testing sera and making standard media, as well as policing the facilities to ensure equipment upkeep and cleanliness. An important function carried out by the Core Director and the full-time technical assistant is training personnel from the investigators? laboratories and helping investigators develop new protocols as needed to carry out their projects. Routine cell culture using established protocols is done by personnel from the individual researcher?s laboratories who use the core facilities. Thus, the Core is well equipped and expertly staffed to support 22 funded projects held by 15 primary investigators.